SACRAMENTO, California — California will offer a special extension to buy health insurance through the state exchange for people who say they weren't aware they would face a tax penalty for being uninsured.

Covered California Executive Director Peter Lee announced the extension until April 30.

He said Friday that as many as 600,000 residents may face a penalty under the Affordable Care Act. The extension does not exempt people from paying the 2014 tax penalty, but would help them avoid bigger penalties in 2015.

Enrollment was previously extended until Sunday for people who did not complete their application by the Feb. 15 deadline.

So far, 1.4 million Californians have signed up for private insurance, short of the agency's 1.7 million goal.

The federal exchange also extended enrollment from March 15 to April 30.